Phonon spectrum of He II with homogeneous momentum and temperature dependence

The energy e{open}_p of a phonon in He II is found to have the form {Mathematical expression}. This result is obtained from a three-phonon renormalized Landau hydrodynamics model of the superfluid. We show how this form for e{open}_p resolves the apparent contradiction between several very recent experiments. We also present several results for the phase and group velocities and the low-temperature specific heat C_vwhich are direct consequences of the homogeneous form of e{open}_p.